myformulas

This app is for anyone who has to calculate formulas: high school and college students in science, engineering, or business courses, as well as teachers or practitioners in any of these fields who need to get quick results when they are not near their computer. It will handle a wider variety of formulas than most hand-held calculators, particularly formulas for which you want to use named variables and change their values frequently. Not only is this app easier to use than most hand-held calculators (being able to use parentheses rather than the tricky reverse Polish format required by most HP machines), it is also easier to use than the formula editing feature of a spreadsheet. Entering formulas is a snap: all you have to do is type in characters as you would with a text editor; the program parser will identify any variables and set up a screen for you to enter their values. Alphabetic and numeric characters are entered on different keypads in order to provide you with larger keys to minimize data entry errors. Close integration makes switching between these keypads very fast and easy.

Once you have entered a formula structure, and the initial values for any variables it might have, you can name and store it for future use. You can scroll through the list of stored formulas and recognize by name or formula structure any that you want to re-use.

Business or financial users will find this app a good complement to the calc_formulas app (by the same author and available for free), which allows the user to select from a list of 27 frequently used financial formulas, but does not have the capability to create new formulas.

The only deficiency in “myformulas” is the absence of a built-in function library. If more than 1000 people will pay $2.50 for this version, I will produce a slightly more expensive version with a function library more complete than any spreadsheet.